Senator Gillibrand, right, in her congressional office with Leive. Note the artwork by her kids on the wall.

I love the art in Senator Kirsten Gillibrand's office. There are stick-figure families by her kids—"I love Mom" scrawled across them—and, just inches away, a John James Audubon painting of a falcon in "attack pose." But being both fierce and family-oriented is Sen. Gillibrand's thing. In the five years since the 47-year-old Democrat took Hillary Clinton's seat representing New York in the U.S. Senate, she's championed laws supporting women and children, gaining rabid fans and ruffling feathers.(She also helped end the military's "don't ask, don't tell" policy.) So what can women of all political persuasions learn about confidence—and work-life balance—from her? I went to the Russell Senate Office Building in Washington, D.C., to find out.

Cindi Leive: So here we are in your office. Every profile of you mentions your sons, Henry and Theo [ages five and 10, respectively], waiting in here while you cast a vote.

Senator Kirsten Gillibrand: Henry's typically here between 3:00 and 5:00 P.M. Yesterday he didn't want to go to his tae kwon do class; he asked to come here!

CL: You arranged to cast your vote from the Senate chamber doorway so you could hold Henry's hand [while he waited outside]. Was that hard to get the OK for?

KG: It took months. But it was necessary. [Laughs.] Henry's only five, so he gets into trouble if he's not supervised.

CL: Have other senators taken advantage?

KG: No. Most of them have wives who take care of the children. I do not have a wife. I have a wonderful husband, but he works in New York City during the week.

CL: I wanted to ask about that! For decades men in leadership jobs have had somebody at home waiting for them, to rub their feet and ask them how their day was. Is there ever a part of you that's like,"OK, honey, you have to move to D.C."?

KG: My husband [Jonathan Gillibrand, a finance manager] lives in D.C. on weekends; his job the last two years has been in New York City. But I have more flexibility than most working moms trying to raise a family. Unfortunately, our [country's] workplace rules are stuck in the seventies, when, out of a block of 10 houses, in more than half of them the husband went to work and the wife stayed home. Now on that same block almost eight of the wives work. That's one reason why I want equal pay for equal work, and why affordable day care, early childhood education, and universal pre-K are so important to me.

CL: You know, April 8 is Equal Pay Day, on which women's wages finally catch up to what men earned the previous year.

KG: It's disgraceful. Women's voices aren't heard often enough. Congress should reflect the population, but with only 20 percent women in the Senate and 18 percent in the House, it just doesn't.

CL: You believe organizations with more women leaders are fairer and more efficient. Have you seen that in the Senate?

KG: Women are good at collaborating and finding common ground.Corporate boards with even one woman are 40 percent less likely to have to restate their earnings!

KG: Yes. President Obama even hosted us once! It gives us a chance to get to know each other as regular people. So when I'm trying to pass something, I can ask Susan Collins [R-Maine], "How do I do this in a way that the Republicans will vote for it?"

CL: What happens at the dinners?

KG: A lot of them are celebratory! I baked pies for Barbara Mikulski's [D-Md.] birthday.

CL: Let's talk about the Military Justice Improvement Act, a bill you introduced that would help survivors of sexual assault in the military. What would you like to see happen next?

KG: We still need a vote on the bill. But it contains the one reform victims asked for: that the decision of whether to proceed to trial not be made by a superior in their chain of command. So many victims said their commanders told them that if they reported their rapes, their careers would end.

CL: I saw someone ask you at a party once how you kept the issue in the headlines. You said, "I just kept talking about it." You didn't wait for it to be a hot topic.

KG: No. When a woman has the opportunity to speak truth to power, it's important that she does, even if it's just trying to get a crosswalk in her neighborhood. That's how social change happens!

CL: Early in your tenure your detractors criticized your stance on the NRA, and the press was extremely focused on your appearance. You told New York magazine that your response was, "Give me six months." How did you know?

KG: I had an amazing advantage: a grandmother [Polly Noonan, an influential confidante of the mayor of Albany] who loved politics. She taught me not to listen to negative press or people. I grew up knowing politics was rough-and-tumble.

CL: You've said that you decided to get into politics when you heard Hillary Clinton speak at the World Conference on Women in Beijing in 1995. But you didn't run for another 11 years. Why?

KG: When Hillary gave her speech, I thought, I should be at that conference. But I was just a corporate lawyer pushing paper. So I joined a women's political group. The more I raised money for other candidates, the more I decided I wanted to do public service.

CL: In your job you ask for votes and money. Sheryl Sandberg, whom we interviewed last month, says that when women ask for something, even a raise, they have to do it carefully to avoid seeming aggressive. Do you ask differently than a man would?

KG: No, but it's hard for women to ask. I tell women candidates soliciting contributions, "It's not about you. It's about what you're fighting for." Women asking for raises should not only know their value, but they should ask with the confidence that they're helping the company to be successful.

CL: You are a forceful and swift public speaker. Did you train yourself?

KG: Definitely. As a lawyer [I had learned] you never speak with emotion. It's about the precise facts.

CL: Well, that's boring!

KG: And that's not possible in politics; it's more helpful to tell a personal story. Then relax and slow down.

CL: So many articles about you mention what you have on. "She's wearing yoga pants!" "She's wearing a beautiful navy dress!" Does this bug you at all?

KG: It's human nature, and I'm as interested as any other woman. When it becomes toxic is when it's all that's being discussed.

CL: When I first met you, you were saying, "I'm dying to lose the baby weight."

KG: After Henry, I had 50 pounds to lose. When he turned one, I finally said, "If I'm going to be productive and efficient, I also need to be happy." I went on a strict diet and focused on gym time. It took a year, but I lost it all. On the days I work out, not only am I friendlier and nicer, I'm more productive!

CL: You meet a lot of young women. What's a bad habit you see them making?

KG: For a lot of them—and I do it too—we doubt ourselves: "Am I qualified?" I would encourage them to be more confident.

CL: Millions of Glamour readers will see this. How can one of them know whether she's the right person to run for office?

KG: If there's an issue she cares about, and what she believes should be done isn't being done, then she is the perfect person to run for office. The drive toward something better is what voters are looking for.

CL: One of my favorite questions: Nobody really "does it all"—what do you not do?

KG: I don't like the phrase having it all. It implies we're being greedy, like "have a second piece of pie." Women are already doing it all. That's why I feel so passionate about workplace reform. We should be cultivating our female workers. The truth of the matter is that women just see problems and solutions differently, and that's valuable.